Copper-Catalyzed Direct Asymmetric Aldol Reaction of Glycine Schiff Bases to Access -β-Hydroxy-α-amino Esters.

This study reported a copper-catalyzed direct asymmetric aldol reaction between aldehydes and glycine Schiff bases with methyl, allyl, and -butyl esters. Additionally, this reaction afforded high yields of -β-hydroxy-α-amino esters with excellent enantio- and diastereoselectivities (93-99% ee, up to >99:1 dr). The aldol reaction accepted aromatic, linear aliphatic, and α-substituted aliphatic aldehydes.